Conventionally, the use of a daylighting member has been suggested as a technique for effectively letting natural light (sunlight) from outside a building into the building through a window pane or the like (see, for example, Patent Literature 1).
The daylighting member includes an optically transparent film (substrate) and a plurality of prismatic bodies (protruding portions) or the like formed on one surface of the optically transparent film. By being bonded to the window pane, the daylighting member changes, with use of the prismatic bodies, the traveling direction of light falling on the window pane and, at the same time, aims the light at a ceiling, a side wall, a floor, or the like inside the building.
Further, the light traveling toward the ceiling is reflected by the ceiling to illuminate the inside of the room and, as such, serves as a substitute for illuminating light.
Therefore, the user of such a daylighting member is expected to bring about an energy-saving effect of saving energy that is consumed by lighting facilities inside a building during the day.